Communication method and device based on common frequency resource for group common transmission in wireless communication system

ABSTRACT

A method by which a terminal receives group common data in a wireless communication system, according to one embodiment of the present disclosure, may comprise the steps of: receiving, from a network, configuration information about a common frequency resource (CFR) for group common data associated with a group common identifier; receiving, from the network, information about a plurality of bandwidth parts (BWPs); receiving, from the network, group common data based on the group common identifier on a bandwidth of a first BWP including the CFR; activating a second BWP; and receiving, from the network, group common data based on the group common identifier on a bandwidth of the second BWP, on the basis of the satisfaction of a specific condition between the second BWP and the CFR.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of InternationalApplication No. PCT/KR2022/006733, filed on May 11, 2022, which claimsthe benefit of earlier filing date and right of priority to KoreanApplication No. 10-2021-0060546, filed on May 11, 2021, the contents ofwhich are all hereby incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present disclosure relates to a wireless communication system, andin more detail, relates to a configuration for a common frequencyresource for group common transmission in a wireless communicationsystem and a communication method and device based thereon.

BACKGROUND

A mobile communication system has been developed to provide a voiceservice while guaranteeing mobility of users. However, a mobilecommunication system has extended even to a data service as well as avoice service, and currently, an explosive traffic increase has causedshortage of resources and users have demanded a faster service, so amore advanced mobile communication system has been required.

The requirements of a next-generation mobile communication system atlarge should be able to support accommodation of explosive data traffic,a remarkable increase in a transmission rate per user, accommodation ofthe significantly increased number of connected devices, very lowEnd-to-End latency and high energy efficiency. To this end, a variety oftechnologies such as Dual Connectivity, Massive Multiple Input MultipleOutput (Massive MIMO), In-band Full Duplex, Non-Orthogonal MultipleAccess (NOMA), Super wideband Support, Device Networking, etc. have beenresearched.

SUMMARY

A technical problem of the present disclosure is to provide acommunication method and device based on a common frequency resource forgroup common transmission in a wireless communication system.

An additional technical problem of the present disclosure is to providea configuration for a common frequency resource for group commontransmission in a wireless communication system, and a communicationmethod and device based on a common frequency resource related to abandwidth part.

The technical objects to be achieved by the present disclosure are notlimited to the above-described technical objects, and other technicalobjects which are not described herein will be clearly understood bythose skilled in the pertinent art from the following description.

A method of receiving group common data by a terminal in a wirelesscommunication system according to an aspect of the present disclosuremay include receiving from a network configuration information for acommon frequency resource (CFR) for group common data associated with agroup common identifier; receiving from the network information on afirst BWP among a plurality of bandwidth parts (BWP); receiving from thenetwork group common data based on the group common identifier on abandwidth of the first BWP including the CFR; receiving from the networkinformation on a second BWP among the plurality of BWPs; activating thesecond BWP; and based on a specific condition between the second BWP andthe CFR being satisfied, receiving from the network group common databased on the group common identifier on a bandwidth of the second BWP.

A method of transmitting group common data by a base station in awireless communication system according to an additional aspect of thepresent disclosure may include transmitting to a terminal configurationinformation for a common frequency resource (CFR) for group common dataassociated with a group common identifier; transmitting to the terminalinformation on a first BWP among a plurality of bandwidth parts (BWP);transmitting to the terminal group common data based on the group commonidentifier on a bandwidth of the first BWP including the CFR;transmitting to the terminal information on a second BWP among theplurality of BWPs; and transmitting to the terminal group common databased on the group common identifier on a bandwidth of the second BWP,and based on a specific condition between the second BWP and the CFRbeing satisfied, group common data based on the group common identifieron a bandwidth of the second BWP activated by the terminal may bereceived in the terminal.

According to an embodiment of the present disclosure, a communicationmethod and device based on a common frequency resource for group commontransmission in a wireless communication system may be provided.

According to an embodiment of the present disclosure, a configurationfor a common frequency resource for group common transmission in awireless communication system, and a communication method and devicebased on a common frequency resource related to a bandwidth part may beprovided.

According to an embodiment of the present disclosure, a method and adevice of performing group common transmission without interruption ordisconnection of data transmission and reception based on a commonfrequency resource which is maintained when changing a bandwidth partmay be provided.

Effects achievable by the present disclosure are not limited to theabove-described effects, and other effects which are not describedherein may be clearly understood by those skilled in the pertinent artfrom the following description.

BRIEF DESCRIPTION OF DRAWINGS

Accompanying drawings included as part of detailed description forunderstanding the present disclosure provide embodiments of the presentdisclosure and describe technical features of the present disclosurewith detailed description.

FIG. 1 illustrates a structure of a wireless communication system towhich the present disclosure may be applied.

FIG. 2 illustrates a frame structure in a wireless communication systemto which the present disclosure may be applied.

FIG. 3 illustrates a resource grid in a wireless communication system towhich the present disclosure may be applied.

FIG. 4 illustrates a physical resource block in a wireless communicationsystem to which the present disclosure may be applied.

FIG. 5 illustrates a slot structure in a wireless communication systemto which the present disclosure may be applied.

FIG. 6 illustrates physical channels used in a wireless communicationsystem to which the present disclosure may be applied and a generalsignal transmission and reception method using them.

FIG. 7 is a diagram for describing a terminal operation for receivinggroup common data based on a common frequency resource according to anexample of the present disclosure.

FIG. 8 is a diagram for describing a base station operation fortransmitting group common data based on a common frequency resourceaccording to an example of the present disclosure.

FIG. 9 is a diagram for describing a CFR configuration according to anexample of the present disclosure.

FIG. 10 is a diagram for describing an example of a HARQ-ACK operationfor group common transmission according to the present disclosure.

FIG. 11 is a diagram which illustrates a block diagram of a wirelesscommunication system according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments according to the present disclosure will bedescribed in detail by referring to accompanying drawings. Detaileddescription to be disclosed with accompanying drawings is to describeexemplary embodiments of the present disclosure and is not to representthe only embodiment that the present disclosure may be implemented. Thefollowing detailed description includes specific details to providecomplete understanding of the present disclosure. However, those skilledin the pertinent art knows that the present disclosure may beimplemented without such specific details.

In some cases, known structures and devices may be omitted or may beshown in a form of a block diagram based on a core function of eachstructure and device in order to prevent a concept of the presentdisclosure from being ambiguous.

In the present disclosure, when an element is referred to as being“connected”, “combined” or “linked” to another element, it may includean indirect connection relation that yet another element presentstherebetween as well as a direct connection relation. In addition, inthe present disclosure, a term, “include” or “have”, specifies thepresence of a mentioned feature, step, operation, component and/orelement, but it does not exclude the presence or addition of one or moreother features, stages, operations, components, elements and/or theirgroups.

In the present disclosure, a term such as “first”, “second”, etc. isused only to distinguish one element from other element and is not usedto limit elements, and unless otherwise specified, it does not limit anorder or importance, etc. between elements. Accordingly, within a scopeof the present disclosure, a first element in an embodiment may bereferred to as a second element in another embodiment and likewise, asecond element in an embodiment may be referred to as a first element inanother embodiment.

A term used in the present disclosure is to describe a specificembodiment, and is not to limit a claim. As used in a described andattached claim of an embodiment, a singular form is intended to includea plural form, unless the context clearly indicates otherwise. A termused in the present disclosure, “and/or”, may refer to one of relatedenumerated items or it means that it refers to and includes any and allpossible combinations of two or more of them. In addition, “/” betweenwords in the present disclosure has the same meaning as “and/or”, unlessotherwise described.

The present disclosure describes a wireless communication network or awireless communication system, and an operation performed in a wirelesscommunication network may be performed in a process in which a device(e.g., a base station) controlling a corresponding wirelesscommunication network controls a network and transmits or receives asignal, or may be performed in a process in which a terminal associatedto a corresponding wireless network transmits or receives a signal witha network or between terminals.

In the present disclosure, transmitting or receiving a channel includesa meaning of transmitting or receiving information or a signal through acorresponding channel. For example, transmitting a control channel meansthat control information or a control signal is transmitted through acontrol channel. Similarly, transmitting a data channel means that datainformation or a data signal is transmitted through a data channel.

Hereinafter, a downlink (DL) means a communication from a base stationto a terminal and an uplink (UL) means a communication from a terminalto a base station. In a downlink, a transmitter may be part of a basestation and a receiver may be part of a terminal. In an uplink, atransmitter may be part of a terminal and a receiver may be part of abase station. A base station may be expressed as a first communicationdevice and a terminal may be expressed as a second communication device.A base station (BS) may be substituted with a term such as a fixedstation, a Node B, an eNB (evolved-NodeB), a gNB (Next GenerationNodeB), a BTS (base transceiver system), an Access Point (AP), a Network(5G network), an AI (Artificial Intelligence) system/module, an RSU(road side unit), a robot, a drone (UAV: Unmanned Aerial Vehicle), an AR(Augmented Reality) device, a VR (Virtual Reality) device, etc. Inaddition, a terminal may be fixed or mobile, and may be substituted witha term such as a UE (User Equipment), an MS (Mobile Station), a UT (userterminal), an MSS (Mobile Subscriber Station), an SS (SubscriberStation), an AMS (Advanced Mobile Station), a WT (Wireless terminal), anMTC (Machine-Type Communication) device, an M2M (Machine-to-Machine)device, a D2D (Device-to-Device) device, a vehicle, an RSU (road sideunit), a robot, an AI (Artificial Intelligence) module, a drone (UAV:Unmanned Aerial Vehicle), an AR (Augmented Reality) device, a VR(Virtual Reality) device, etc.

The following description may be used for a variety of radio accesssystems such as CDMA, FDMA, TDMA, OFDMA, SC-FDMA, etc. CDMA may beimplemented by a wireless technology such as UTRA (Universal TerrestrialRadio Access) or CDMA2000. TDMA may be implemented by a radio technologysuch as GSM (Global System for Mobile communications)/GPRS (GeneralPacket Radio Service)/EDGE (Enhanced Data Rates for GSM Evolution).OFDMA may be implemented by a radio technology such as IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, E-UTRA (Evolved UTRA), etc.UTRA is a part of a UMTS (Universal Mobile Telecommunications System).3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is apart of an E-UMTS (Evolved UMTS) using E-UTRA and LTE-A (Advanced)/LTE-Apro is an advanced version of 3GPP LTE. 3GPP NR (New Radio or New RadioAccess Technology) is an advanced version of 3GPP LTE/LTE-A/LTE-A pro.

To clarify description, it is described based on a 3GPP communicationsystem (e.g., LTE-A, NR), but a technical idea of the present disclosureis not limited thereto. LTE means a technology after 3GPP TS (TechnicalSpecification) 36.xxx Release 8. In detail, an LTE technology in orafter 3GPP TS 36.xxx Release 10 is referred to as LTE-A and an LTEtechnology in or after 3GPP TS 36.xxx Release 13 is referred to as LTE-Apro. 3GPP NR means a technology in or after TS 38.xxx Release 15. LTE/NRmay be referred to as a 3GPP system. “xxx” means a detailed number for astandard document. LTE/NR may be commonly referred to as a 3GPP system.For a background art, a term, an abbreviation, etc. used to describe thepresent disclosure, matters described in a standard document disclosedbefore the present disclosure may be referred to. For example, thefollowing document may be referred to.

For 3GPP LTE, TS 36.211 (physical channels and modulation), TS 36.212(multiplexing and channel coding), TS 36.213 (physical layerprocedures), TS 36.300 (overall description), TS 36.331 (radio resourcecontrol) may be referred to.

For 3GPP NR, TS 38.211 (physical channels and modulation), TS 38.212(multiplexing and channel coding), TS 38.213 (physical layer proceduresfor control), TS 38.214 (physical layer procedures for data), TS 38.300(NR and NG-RAN (New Generation-Radio Access Network) overalldescription), TS 38.331 (radio resource control protocol specification)may be referred to.

Abbreviations of terms which may be used in the present disclosure isdefined as follows.

BM: beam management

CQI: Channel Quality Indicator

CRI: channel state information-reference signal resource indicator

CSI: channel state information

CSI-IM: channel state information-interference measurement

CSI-RS: channel state information-reference signal

DMRS: demodulation reference signal

FDM: frequency division multiplexing

FFT: fast Fourier transform

IFDMA: interleaved frequency division multiple access

IFFT: inverse fast Fourier transform

L1-RSRP: Layer 1 reference signal received power

L1-RSRQ: Layer 1 reference signal received quality

MAC: medium access control

NZP: non-zero power

OFDM: orthogonal frequency division multiplexing

PDCCH: physical downlink control channel

PDSCH: physical downlink shared channel

PMI: precoding matrix indicator

RE: resource element

RI: Rank indicator

RRC: radio resource control

RSSI: received signal strength indicator

Rx: Reception

QCL: quasi co-location

SINR: signal to interference and noise ratio

SSB (or SS/PBCH block): Synchronization signal block (including PSS(primary synchronization signal), SSS (secondary synchronization signal)and PBCH (physical broadcast channel))

TDM: time division multiplexing

TRP: transmission and reception point

TRS: tracking reference signal

Tx: transmission

UE: user equipment

ZP: zero power

Overall System

As more communication devices have required a higher capacity, a needfor an improved mobile broadband communication compared to the existingradio access technology (RAT) has emerged. In addition, massive MTC(Machine Type Communications) providing a variety of services anytimeand anywhere by connecting a plurality of devices and things is also oneof main issues which will be considered in a next-generationcommunication. Furthermore, a communication system design considering aservice/a terminal sensitive to reliability and latency is alsodiscussed. As such, introduction of a next-generation RAT consideringeMBB(enhanced mobile broadband communication), mMTC(massive MTC),URLLC(Ultra-Reliable and Low Latency Communication), etc. is discussedand, for convenience, a corresponding technology is referred to as NR inthe present disclosure. NR is an expression which represents an exampleof a 5G RAT.

A new RAT system including NR uses an OFDM transmission method or atransmission method similar to it. A new RAT system may follow OFDMparameters different from OFDM parameters of LTE. Alternatively, a newRAT system follows a numerology of the existing LTE/LTE-A as it is, butmay support a wider system bandwidth (e.g., 100 MHz). Alternatively, onecell may support a plurality of numerologies. In other words, terminalswhich operate in accordance with different numerologies may coexist inone cell.

A numerology corresponds to one subcarrier spacing in a frequencydomain. As a reference subcarrier spacing is scaled by an integer N, adifferent numerology may be defined.

FIG. 1 illustrates a structure of a wireless communication system towhich the present disclosure may be applied.

In reference to FIG. 1 , NG-RAN is configured with gNBs which provide acontrol plane (RRC) protocol end for a NG-RA (NG-Radio Access) userplane (i.e., a new AS (access stratum) sublayer/PDCP (Packet DataConvergence Protocol)/RLC (Radio Link Control)/MAC/PHY) and UE. The gNBsare interconnected through a Xn interface. The gNB, in addition, isconnected to an NGC (New Generation Core) through an NG interface. Inmore detail, the gNB is connected to an AMF (Access and MobilityManagement Function) through an N2 interface, and is connected to a UPF(User Plane Function) through an N3 interface.

FIG. 2 illustrates a frame structure in a wireless communication systemto which the present disclosure may be applied.

A NR system may support a plurality of numerologies. Here, a numerologymay be defined by a subcarrier spacing and a cyclic prefix (CP)overhead. Here, a plurality of subcarrier spacings may be derived byscaling a basic (reference) subcarrier spacing by an integer N (or, p).In addition, although it is assumed that a very low subcarrier spacingis not used in a very high carrier frequency, a used numerology may beselected independently from a frequency band. In addition, a variety offrame structures according to a plurality of numerologies may besupported in a NR system.

Hereinafter, an OFDM numerology and frame structure which may beconsidered in a NR system will be described. A plurality of OFDMnumerologies supported in a NR system may be defined as in the followingTable 1.

TABLE 1 μ Δf = 2^(μ) · 15 [kHz] CP 0 15 Normal 1 30 Normal 2 60 Normal,Extended 3 120 Normal 4 240 Normal

NR supports a plurality of numerologies (or subcarrier spacings (SCS))for supporting a variety of 5G services. For example, when a SCS is 15kHz, a wide area in traditional cellular bands is supported, and when aSCS is 30 kHz/60 kHz, dense-urban, lower latency and a wider carrierbandwidth are supported, and when a SCS is 60 kHz or higher, a bandwidthwider than 24.25 GHz is supported to overcome a phase noise.

An NR frequency band is defined as a frequency range in two types (FR1,FR2). FR1, FR2 may be configured as in the following Table 2. Inaddition, FR2 may mean a millimeter wave (mmW).

TABLE 2 Frequency Corresponding Range frequency Subcarrier designationrange Spacing FR1  410 MHz-7125 MHz  15, 30, 60 kHz FR2 24250 MHz-52600MHz 60, 120, 240 kHz

Regarding a frame structure in an NR system, a size of a variety offields in a time domain is expresses as a multiple of a time unit ofT_(c)=1/(Δf_(max)·N_(f)). Here, Δf_(max) is 480·10³ Hz and N_(f) is4096. Downlink and uplink transmission is configured (organized) with aradio frame having a duration of T_(f)=1/(Δf_(max)N_(f)/100)·T_(c)=10ms. Here, a radio frame is configured with 10 subframes having aduration of T_(sf)=(Δf_(max)N_(f)/1000)·T_(c)=1 ms, respectively. Inthis case, there may be one set of frames for an uplink and one set offrames for a downlink. In addition, transmission in an uplink frame No.i from a terminal should start earlier byT_(TA)=(N_(TA)+N_(TA,offset))T_(c) than a corresponding downlink framein a corresponding terminal starts. For a subcarrier spacingconfiguration μ, slots are numbered in an increasing order of n_(s)^(μ)∈{0, . . . , N_(slot) ^(subframe,μ)−1} in a subframe and arenumbered in an increasing order of n_(s,f) ^(μ)∈{0, . . . , N_(slot)^(frame,μ)−1} in a radio frame. One slot is configured with N_(symb)^(slot) consecutive OFDM symbols and N_(symb) ^(slot) is determinedaccording to CP. A start of a slot n_(s) ^(μ)in a subframe is temporallyarranged with a start of an OFDM symbol n_(s) ^(μ)N_(symb) ^(slot) inthe same subframe. All terminals may not perform transmission andreception at the same time, which means that all OFDM symbols of adownlink slot or an uplink slot may not be used.

Table 3 represents the number of OFDM symbols per slot (N_(symb)^(slot)), the number of slots per radio frame (N_(slot) ^(subframe,μ))and the number of slots per subframe (N_(slot) ^(subframe,μ)) in anormal CP and Table 4 represents the number of OFDM symbols per slot,the number of slots per radio frame and the number of slots per subframein an extended CP.

TABLE 3 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

TABLE 4 μ N_(symb) ^(slot) N_(slot) ^(frame, μ) N_(slot) ^(subframe, μ)2 12 40 4

FIG. 2 is an example on μ=2 (SCS is 60 kHz), 1 subframe may include 4slots referring to Table 3. 1 subframe={1,2,4} slot shown in FIG. 2 isan example, the number of slots which may be included in 1 subframe isdefined as in Table 3 or Table 4. In addition, a mini-slot may include2, 4 or 7 symbols or more or less symbols.

Regarding a physical resource in a NR system, an antenna port, aresource grid, a resource element, a resource block, a carrier part,etc. may be considered. Hereinafter, the physical resources which may beconsidered in an NR system will be described in detail.

First, in relation to an antenna port, an antenna port is defined sothat a channel where a symbol in an antenna port is carried can beinferred from a channel where other symbol in the same antenna port iscarried. When a large-scale property of a channel where a symbol in oneantenna port is carried may be inferred from a channel where a symbol inother antenna port is carried, it may be said that 2 antenna ports arein a QC/QCL(quasi co-located or quasi co-location) relationship. In thiscase, the large-scale property includes at least one of delay spread,doppler spread, frequency shift, average received power, receivedtiming.

FIG. 3 illustrates a resource grid in a wireless communication system towhich the present disclosure may be applied.

In reference to FIG. 3 , it is illustratively described that a resourcegrid is configured with N_(RB) ^(μ)N_(sc) ^(RB) subcarriers in afrequency domain and one subframe is configured with 14·2^(μ) OFDMsymbols, but it is not limited thereto. In an NR system, a transmittedsignal is described by OFDM symbols of 2^(μ)N_(symb) ^((μ)) and one ormore resource grids configured with N_(RB) ^(μ)N_(sc) ^(RB) subcarriers.Here, N_(RB) ^(μ)≤N_(RB) ^(max,μ). The N_(RB) ^(max,μ) represents amaximum transmission bandwidth, which may be different between an uplinkand a downlink as well as between numerologies. In this case, oneresource grid may be configured per μ and antenna port p. Each elementof a resource grid for μ and an antenna port p is referred to as aresource element and is uniquely identified by an index pair (k,l′).Here, k=0, . . . , N_(RB) ^(μ)N_(sc) ^(RB)−1 is an index in a frequencydomain and l′=0, . . . , 2^(μ)N_(symb) ^((μ))−1 refers to a position ofa symbol in a subframe. When referring to a resource element in a slot,an index pair (k,l) is used. Here, l=0, . . . , N_(symb) ^(μ)−1. Aresource element (k,l′) for p and an antenna port p corresponds to acomplex value, a_(k,l′) ^((p,μ)). When there is no risk of confusion orwhen a specific antenna port or numerology is not specified, indexes pand μ may be dropped, whereupon a complex value may be a_(k,l′) ^((p))or a_(k,l′). In addition, a resource block (RB) is defined as N_(sc)^(RB)=12 consecutive subcarriers in a frequency domain.

Point A plays a role as a common reference point of a resource blockgrid and is obtained as follows.

offsetToPointA for a primary cell (PCell) downlink represents afrequency offset between point A and the lowest subcarrier of the lowestresource block overlapped with a SS/PBCH block which is used by aterminal for an initial cell selection. It is expressed in resourceblock units assuming a 15 kHz subcarrier spacing for FR1 and a 60 kHzsubcarrier spacing for FR2.

absoluteFrequencyPointA represents a frequency-position of point Aexpressed as in ARFCN (absolute radio-frequency channel number).

Common resource blocks are numbered from 0 to the top in a frequencydomain for a subcarrier spacing configuration μ. The center ofsubcarrier 0 of common resource block 0 for a subcarrier spacingconfiguration μis identical to ‘point A’. A relationship between acommon resource block number n_(CRB) ^(μ) and a resource element (k,l)for a subcarrier spacing configuration μ in a frequency domain is givenas in the following Equation 1.

$\begin{matrix}{n_{CRB}^{\mu} = \left\lfloor \frac{k}{N_{sc}^{RB}} \right\rfloor} & \left\lbrack {{Equation}1} \right\rbrack\end{matrix}$

In Equation 1, k is defined relatively to point A so that k=0corresponds to a subcarrier centering in point A. Physical resourceblocks are numbered from 0 to N_(BWP,i) ^(size,μ)−1 in a bandwidth part(BWP) and i is a number of a BWP. A relationship between a physicalresource block nPRB and a common resource block n_(CRB) in BWP i isgiven by the following Equation 2.

n _(CRB) ^(μ) =n _(PRB) ^(μ) N _(BWP,i) ^(start,μ)  [Equation 2]

N_(BWP,i) ^(start,μ) is a common resource block that a BWP startsrelatively to common resource block 0.

FIG. 4 illustrates a physical resource block in a wireless communicationsystem to which the present disclosure may be applied. And, FIG. 5illustrates a slot structure in a wireless communication system to whichthe present disclosure may be applied.

In reference to FIG. 4 and FIG. 5 , a slot includes a plurality ofsymbols in a time domain. For example, for a normal CP, one slotincludes 7 symbols, but for an extended CP, one slot includes 6 symbols.

A carrier includes a plurality of subcarriers in a frequency domain. AnRB (Resource Block) is defined as a plurality of (e.g., 12) consecutivesubcarriers in a frequency domain. A BWP(Bandwidth Part) is defined as aplurality of consecutive (physical) resource blocks in a frequencydomain and may correspond to one numerology (e.g., an SCS, a CP length,etc.). A carrier may include a maximum N (e.g., 5) BWPs. A datacommunication may be performed through an activated BWP and only one BWPmay be activated for one terminal. In a resource grid, each element isreferred to as a resource element (RE) and one complex symbol may bemapped.

In an NR system, up to 400 MHz may be supported per component carrier(CC). If a terminal operating in such a wideband CC always operatesturning on a radio frequency (FR) chip for the whole CC, terminalbattery consumption may increase. Alternatively, when severalapplication cases operating in one wideband CC (e.g., eMBB, URLLC, Mmtc,V2X, etc.) are considered, a different numerology (e.g., a subcarrierspacing, etc.) may be supported per frequency band in a correspondingCC. Alternatively, each terminal may have a different capability for themaximum bandwidth. By considering it, a base station may indicate aterminal to operate only in a partial bandwidth, not in a full bandwidthof a wideband CC, and a corresponding partial bandwidth is defined as abandwidth part (BWP) for convenience. A BWP may be configured withconsecutive RBs on a frequency axis and may correspond to one numerology(e.g., a subcarrier spacing, a CP length, a slot/a mini-slot duration).

Meanwhile, a base station may configure a plurality of BWPs even in oneCC configured to a terminal. For example, a BWP occupying a relativelysmall frequency domain may be configured in a PDCCH monitoring slot, anda PDSCH indicated by a PDCCH may be scheduled in a greater BWP.Alternatively, when UEs are congested in a specific BWP, some terminalsmay be configured with other BWP for load balancing. Alternatively,considering frequency domain inter-cell interference cancellationbetween neighboring cells, etc., some middle spectrums of a fullbandwidth may be excluded and BWPs on both edges may be configured inthe same slot. In other words, a base station may configure at least oneDL/UL BWP to a terminal associated with a wideband CC. A base stationmay activate at least one DL/UL BWP of configured DL/UL BWP(s) at aspecific time (by L1 signaling or MAC CE(Control Element) or RRCsignaling, etc.). In addition, a base station may indicate switching toother configured DL/UL BWP (by L1 signaling or MAC CE or RRC signaling,etc.). Alternatively, based on a timer, when a timer value is expired,it may be switched to a determined DL/UL BWP. Here, an activated DL/ULBWP is defined as an active DL/UL BWP. But, a configuration on a DL/ULBWP may not be received when a terminal performs an initial accessprocedure or before a RRC connection is set up, so a DL/UL BWP which isassumed by a terminal under these situations is defined as an initialactive DL/UL BWP.

FIG. 6 illustrates physical channels used in a wireless communicationsystem to which the present disclosure may be applied and a generalsignal transmission and reception method using them.

In a wireless communication system, a terminal receives informationthrough a downlink from a base station and transmits information throughan uplink to a base station. Information transmitted and received by abase station and a terminal includes data and a variety of controlinformation and a variety of physical channels exist according to atype/a usage of information transmitted and received by them.

When a terminal is turned on or newly enters a cell, it performs aninitial cell search including synchronization with a base station or thelike (S601). For the initial cell search, a terminal may synchronizewith a base station by receiving a primary synchronization signal (PSS)and a secondary synchronization signal (SSS) from a base station andobtain information such as a cell identifier (ID), etc. After that, aterminal may obtain broadcasting information in a cell by receiving aphysical broadcast channel (PBCH) from a base station. Meanwhile, aterminal may check out a downlink channel state by receiving a downlinkreference signal (DL RS) at an initial cell search stage.

A terminal which completed an initial cell search may obtain moredetailed system information by receiving a physical downlink controlchannel (PDCCH) and a physical downlink shared channel (PDSCH) accordingto information carried in the PDCCH (S602).

Meanwhile, when a terminal accesses to a base station for the first timeor does not have a radio resource for signal transmission, it mayperform a random access (RACH) procedure to a base station (S603 toS606). For the random access procedure, a terminal may transmit aspecific sequence as a preamble through a physical random access channel(PRACH) (S603 and S605) and may receive a response message for apreamble through a PDCCH and a corresponding PDSCH (S604 and S606). Acontention based RACH may additionally perform a contention resolutionprocedure.

A terminal which performed the above-described procedure subsequentlymay perform PDCCH/PDSCH reception (S607) and PUSCH (Physical UplinkShared Channel)/PUCCH (physical uplink control channel) transmission(S608) as a general uplink/downlink signal transmission procedure. Inparticular, a terminal receives downlink control information (DCI)through a PDCCH. Here, DCI includes control information such as resourceallocation information for a terminal and a format varies depending onits purpose of use.

Meanwhile, control information which is transmitted by a terminal to abase station through an uplink or is received by a terminal from a basestation includes a downlink/uplink ACK/NACK(Acknowledgement/Non-Acknowledgement) signal, a CQI (Channel QualityIndicator), a PMI (Precoding Matrix Indicator), a RI (Rank Indicator),etc. For a 3GPP LTE system, a terminal may transmit control informationof the above-described CQI/PMI/RI, etc. through a PUSCH and/or a PUCCH.

Table 5 represents an example of a DCI format in an NR system.

TABLE 5 DCI Format Use 0_0 Scheduling of a PUSCH in one cell 0_1Scheduling of one or multiple PUSCHs in one cell, or indication of cellgroup downlink feedback information to a UE 0_2 Scheduling of a PUSCH inone cell 1_0 Scheduling of a PDSCH in one DL cell 1_1 Scheduling of aPDSCH in one cell 1_2 Scheduling of a PDSCH in one cell

In reference to Table 5, DCI formats 0_0, 0_1 and 0_2 may includeresource information (e.g., UL/SUL (Supplementary UL), frequencyresource allocation, time resource allocation, frequency hopping, etc.),information related to a transport block (TB) (e.g., MCS (ModulationCoding and Scheme), a NDI (New Data Indicator), a RV (RedundancyVersion), etc.), information related to a HARQ (Hybrid-Automatic Repeatand request) (e.g., a process number, a DAI (Downlink Assignment Index),PDSCH-HARQ feedback timing, etc.), information related to multipleantennas (e.g., DMRS sequence initialization information, an antennaport, a CSI request, etc.), power control information (e.g., PUSCH powercontrol, etc.) related to scheduling of a PUSCH and control informationincluded in each DCI format may be pre-defined.

DCI format 0_0 is used for scheduling of a PUSCH in one cell.Information included in DCI format 0_0 is CRC (cyclic redundancy check)scrambled by a C-RNTI (Cell Radio Network Temporary Identifier) or aCS-RNTI (Configured Scheduling RNTI) or a MCS-C-RNTI (Modulation CodingScheme Cell RNTI) and transmitted.

DCI format 0_1 is used to indicate scheduling of one or more PUSCHs orconfigure grant (CG) downlink feedback information to a terminal in onecell. Information included in DCI format 0_1 is CRC scrambled by aC-RNTI or a CS-RNTI or a SP-CSI-RNTI (Semi-Persistent CSI RNTI) or aMCS-C-RNTI and transmitted.

DCI format 0_2 is used for scheduling of a PUSCH in one cell.Information included in DCI format 0 2 is CRC scrambled by a C-RNTI or aCS-RNTI or a SP-CSI-RNTI or a MCS-C-RNTI and transmitted.

Next, DCI formats 1_0, 1_1 and 1_2 may include resource information(e.g., frequency resource allocation, time resource allocation, VRB(virtual resource block)-PRB (physical resource block) mapping, etc.),information related to a transport block (TB) (e.g., MCS, NDI, RV,etc.), information related to a HARQ (e.g., a process number, DAI,PDSCH-HARQ feedback timing, etc.), information related to multipleantennas (e.g., an antenna port, a TCI (transmission configurationindicator), a SRS (sounding reference signal) request, etc.),information related to a PUCCH (e.g., PUCCH power control, a PUCCHresource indicator, etc.) related to scheduling of a PDSCH and controlinformation included in each DCI format may be pre-defined.

DCI format 1_0 is used for scheduling of a PDSCH in one DL cell.Information included in DCI format 1_0 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

DCI format 1_1 is used for scheduling of a PDSCH in one cell.Information included in DCI format 1_1 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

DCI format 1_2 is used for scheduling of a PDSCH in one cell.Information included in DCI format 1_2 is CRC scrambled by a C-RNTI or aCS-RNTI or a MCS-C-RNTI and transmitted.

MBMS (Multimedia Broadcast Multicast Service)

MBMS may include a single frequency network (SFN) scheme in which aplurality of base stations or a plurality of cells are synchronized totransmit the same data to a terminal, and a single cell point tomultipoint (SC-PTM) scheme for broadcasting within the correspondingcell coverage through the PDCCH/PDSCH channel.

SFN scheme may be used to provide a broadcast service to a wide area(e.g., MBMS area) through resources allocated semi-statically inadvance. A multicast broadcast single frequency network (MBSFN) provideslogical channels, a multicast control channel (MCCH) and a multicasttraffic channel (MTCH), and both of the MCCH and the MTCH are mapped toa transport channel, a multicast channel (MCH), and the MCH is mapped toa physical channel, a physical multicast channel (PMCH). That is, aplurality of base stations/cells may be synchronized to provide the samedata to a terminal through the PMCH. One base station/cell may belong toa plurality of MBSFN areas. In addition, it may be required to configurethe MBSFN subframe for the MBSFN service.

SC-PTM scheme may be mainly used to provide a broadcast service onlywithin a cell coverage through dynamic resources. SC-PTM provides onelogical channel, SC-MCCH (Single Cell Multicast Control Channel) and oneor more logical channels SC-MTCH (Single Cell Multicast TrafficChannel). These logical channels (i.e., SC-MCCH and SC-MTCH) are mappedto the transport channel, DL-SCH, and the transport channel DL-SCH ismapped to the physical channel PDSCH. A PDSCH transmitting datacorresponding to the SC-MCCH or SC-MTCH is scheduled through a PDCCHthat is CRC scrambled with a group-radio network temporary identifier(G-RNTI). Here, a temporary mobile group identity (TMGI) correspondingto the MBMS service ID may be mapped one-to-one with a specific G-RNTIvalue. Accordingly, if the base station provides a plurality of MBMSservices, a plurality of G-RNTI values may be allocated for SC-PTMtransmission. One or more terminals may perform PDCCH monitoring using aspecific G-RNTI to receive a specific MBMS service. Here, adiscontinuous reception (DRX) on-duration period dedicated to SC-PTM maybe configured for a specific MBMS service/specific G-RNTI. In this case,the corresponding terminals may wake up only for a specific on-durationperiod and perform PDCCH monitoring for the G-RNTI.

SPS (Semi-Persistent Scheduling)

The base station may provide a specific terminal with SPS configurationdedicated to the terminal, and allocate one or more downlink SPStransmission resources that are repeated according to a configuredperiod. DCI of terminal-dedicated (or terminal-specific) PDCCH mayindicate activation (SPS activation) of a specific SPS configurationindex. The terminal may perform downlink reception through the activatedSPS transmission resource. Such SPS transmission resource may be usedfor initial HARQ transmission. The base station may allocate aretransmission resource of a specific SPS configuration index throughDCI of PDCCH dedicated to a terminal. For example, when the terminalreports HARQ NACK for the SPS transmission resource, the base stationmay allocate the retransmission resource through DCI so that theterminal may receive downlink retransmission.

DCI of PDCCH dedicated to a terminal may indicate release ordeactivation of a specific SPS configuration index. In this case, thecorresponding terminal does not receive the SPS transmission resourcefor which release/deactivation is indicated.

CRC of DCl/PDCCH for activation/retransmission/deactivation for SPSconfiguration/resource may be scrambled by configured scheduling-radionetwork temporary identifier (CS-RNTI).

MBS (Multicast Broadcast Service)

In the NR-based wireless communication system, introduction of a newMBS-based DL broadcast or DL multicast transmission scheme, which isdistinct from the aforementioned MBMS (e.g., MBSFN or SC-PTM), is beingdiscussed. For example, the network side (e.g., base station/cell/TRP)may provide a point-to-multipoint (PTM) transmission scheme and apoint-to-point (PTP) transmission scheme for DL broadcast or DLmulticast transmission.

In the PTM transmission scheme for MBS, the base station may transmit agroup common (or group-specific) PDCCH and a group common PDSCH to aplurality of terminals. A plurality of terminals may simultaneouslyreceive the same group common PDCCH transmission and group common PDSCHtransmission, and decode the same MBS data.

In the PTP transmission scheme for MBS, the base station may transmit aterminal-dedicated (or terminal-specific) PDCCH and a terminal-dedicatedPDSCH to a specific terminal. The corresponding single terminal mayreceive the terminal-dedicated PDCCH and a terminal-dedicated PDSCH.When there are a plurality of terminals receiving the same MBS service,the base station may individually transmit the same MBS data to each ofthe plurality of terminals through different terminal-dedicated PDCCHsand terminal-dedicated PDSCHs.

In a PTM transmission method, a base station transmits a plurality ofgroup common PDSCHs to terminals. A base station may configure a CFR(Common Frequency Resource) for PTM transmission to a terminal. Forexample, a CFR may be referred to as a common same frequency resourcewhich is allocated to a plurality of terminals or may be referred to asa frequency resource which is commonly used to provide a variety ofMBSs. In addition, a CFR may be referred to as a BWP for a MBS bydistinguishing from the existing terminal-dedicated (orterminal-specific) BWP. A CFR may be associated with aterminal-dedicated BWP.

As described above, at least one terminal-dedicated BWP may beconfigured for a terminal and when a plurality of BWPs are configured,one BWP of them may be activated. For example, a BWP configuration maybe provided to a terminal through higher layer (e.g., RRC) signaling andBWP activation may be indicated to a terminal through DCI. When a secondBWP is indicated/activated in a state that a first BWP is activated, anactive BWP may be changed or switched. As such, when BWP switchingbetween terminal-dedicated BWPs is applied, there is a problem that itis not clear whether a terminal should maintain or change a CFR.

In examples of the present disclosure, when a specific condition betweenan active BWP and a CFR is satisfied, a new method of maintaining a CFRregarding BWP change or switching is described. Accordingly, althoughBWP change or switching occurs, MBS data through a CFR may be receivedwithout interruption or disconnection. Hereinafter, in a wirelesscommunication system which supports group common transmission like aMBS, specific examples of the present disclosure on a configuration fora CFR and a communication based on a configuration for a CFR aredescribed.

FIG. 7 is a diagram for describing a terminal operation for receivingMBS data based on a common frequency resource according to an example ofthe present disclosure.

In S710, a terminal may receive from a network (e.g., a base station)configuration information on a CFR for a MBS associated with a groupcommon identifier.

A group common identifier, for example, may be a G-RNTI. A G-RNTI may beassociated with a specific MBS (i.e., a specific MBS service or aspecific MBS session). In addition, a G-RNTI may be associated with aTGMI of a specific MBS. In order to receive such a MBS, a CFR may beconfigured for a terminal. In other words, a terminal may receive MBSdata through a CFR. MBS data may be received through a broadcast PDSCHor a multicast PDSCH.

In S720, a terminal may receive from a network information on a firstBWP among a plurality of BWPs.

Configuration information on a plurality of BWPs may be provided for aterminal for one serving cell. When one BWP (e.g., a first BWP) of aplurality of BWPs is indicated, a corresponding BWP may be activated. Inother words, a terminal may receive downlink data which includes MBSdata on an active BWP. Information on a first BWP may be included in DCI(e.g., DCI format 1 series) which includes scheduling information ofdownlink data (e.g., a PDSCH).

In S730, a terminal may receive from a network MBS data based on a groupcommon identifier on a first BWP which includes a CFR.

A CFR is configured to receive MBS data, so when an activated first BWPentirely includes a CFR (e.g., includes all resource blocks of afrequency resource provided by CFR configuration information), MBS datamay be received on a first BWP (or on a CFR in a first BWP).Additionally, in order to receive MBS data on a first BWP, it may berequired to satisfy a condition that a numerology of a first BWP is thesame as a numerology of a CFR (e.g., a SCS and CP length).

Receiving MBS data based on a group common identifier may includemonitoring a PDCCH for detecting a DCI format which is CRC-scrambled bya group common identifier and receiving a PDSCH scheduled by a detectedDCI format (i.e., based on DL assignment information in DCI).

In S740, a terminal may receive from a network information on a secondBWP among a plurality of BWPs.

Information on a second BWP may correspond to information indicatingactivation of a second BWP. When it is assumed that only one BWP may beactivated simultaneously in a terminal, an indication for a second BWPmay correspond to an indication to deactivate a currently activatedfirst BWP and activate a second BWP.

In S750, a terminal may receive from a network MBS data based on a groupcommon identifier on a second BWP based on a specific condition betweena second BWP and a CFR being satisfied.

A specific condition may include that a second BWP and a CFR have thesame numerology (e.g., a SCS and CP length) and a CFR is entirelyincluded in a second BWP (e.g., including all resource blocks of afrequency resource provided by CFR configuration information).

If a CFR is entirely included in a first BWP and has the samenumerology, but is not included in a second BWP or has a numerologydifferent from a second BWP, a terminal may not perform an operation ofreceiving MBS data on an activated second BWP.

A configuration for a CFR may be applied equally to a first BWP and asecond BWP. In addition, a configuration for a PDSCH for a MBSassociated with a group common identifier may be applied equally to afirst BWP and a second BWP. Accordingly, although BWP switching orchange is performed, a terminal may receive MBS data through the sameCFR without interruption or disconnection.

FIG. 8 is a diagram for describing a base station operation fortransmitting MBS data based on a common frequency resource according toan example of the present disclosure.

In S810, a base station may transmit to a terminal configurationinformation on a CFR for a MBS associated with a group commonidentifier.

In S820, a base station may transmit to a terminal information on afirst BWP among a plurality of BWPs.

In S830, a base station may transmit to a terminal MBS data based on agroup common identifier on a first BWP which includes a CFR.

In S840, a base station may transmit to a terminal information on asecond BWP among a plurality of BWPs.

In S850, a base station may transmit to a terminal MBS data based on agroup common identifier on a second BWP.

A terminal may receive MBS data based on a group common identifier on asecond BWP based on a specific condition between a second BWP and a CFRbeing satisfied.

In S810 to S850, a description in S710 to S750 of FIG. 7 may be appliedequally and overlapping contents are omitted for brevity.

FIG. 9 is a diagram for describing a CFR configuration according to anexample of the present disclosure.

It may be assumed that a CFR is confined to at least one (i.e., aplurality of) BWP (or activated BWP) having the same numerology. When aCFR is confined to a specific BWP, it means that a CFR is entirelyincluded in a corresponding BWP (in a frequency domain). A configurationfor a corresponding CFR may be applied equally to the plurality of BWPs.When a CFR configuration is applied equally to a plurality of BWPs, itmay mean that a corresponding CFR is associated with a plurality ofBWPs. Alternatively, a configuration for a CFR is provided independentlyor separately without being subordinate to a plurality of BWPs, so thesame CFR configuration may be applied equally without distinguishing aplurality of BWPs.

For BWP switching between a plurality of BWPs associated with the sameCFR, a terminal may not change a CFR. In other words, a terminal maymaintain a CFR configuration when changing/switching a BWP. Accordingly,a terminal may receive MBS data during/after BWP switching. For example,a terminal may maintain a CFR configuration before and after BWPswitching and continuously receive transmission/retransmission of a PTMPDSCH of a specific transport block (TB) and/ortransmission/retransmission of a PTP PDSCH.

In addition, for BWP switching between BWPs associated with the sameCFR, a terminal may maintain a PDCCH configuration, a PDSCHconfiguration, a SPS configuration, a PUCCH configuration, etc. for acorresponding CFR.

A CFR configuration provided to a terminal from a network may include ormay be associated with a group common PDSCH configuration, a groupcommon identifier (e.g., a G-RNTI), etc.

In addition, a group common identifier for a CFR may be configured for aterminal. Furthermore, a group common identifier may be associated witha MBS service having a TGMI, so a group common identifier may be alsoconfigured for at least one of a CFR or a MBS service.

In an example of FIG. 9 , it is assumed that a CFR (CFR) has a firstnumerology (num1). It is assumed that a first BWP(BWP1) has a firstnumerology (num1). In other words, it is assumed that a CFR and BWP1have the same numerology (num1). A numerology may be specified by atleast one of a SCS or CP length.

In an example (a) of FIG. 9 , It is assumed that a second BWP(BWP2) hasa first numerology (num1). In this case, a CFR, BWP1, and BWP2 have thesame numerology and a CFR is completely contained in BWP1 and is alsocompletely contained in BWP2. In this case, although switching/change isperformed from BWP1 to BWP2, a terminal may receive MBS data through aCFR on BWP1 and may also receive MBS data on BWP2 while a CFRconfiguration is maintained.

In an example (b) of FIG. 9 , it is assumed that BWP2 has a secondnumerology (num2). A CFR is completely contained in BWP1 and is alsocompletely contained in BWP2, but a numerology of a CRF and BWP2 isdifferent as it is numl and num2. In this case, a terminal may receiveMBS data through a CFR on BWP1, but it may not perform an operation ofreceiving MBS data through a CFR on BWP2.

In an example (c) of FIG. 9 , all of a CFR, BWP1, and BWP2 have the samenumerology (numl), but a CFR is not completely included in BWP2. In thiscase, a terminal may receive MBS data through a CFR on BWP1, but it maynot perform an operation of receiving MBS data through a CFR on BWP2.

As described in the above-described examples, according to the presentdisclosure, although BWP switching is performed, a CFR configuration maybe maintained and MBS data reception may be performed on a correspondingactive BWP when a specific condition between a CFR and an active BWP issatisfied. Accordingly, even after BWP switching, MBS data receptionthrough a CFR may continue.

Hereinafter, specific examples of the present disclosure are described.

FIG. 10 is a diagram for describing an example of a MBS HARQ-ACKoperation according to the present disclosure.

In the present disclosure, MBS HARQ-ACK includes HARQ-ACK for PTM PDSCHbased MBS service downlink transmission and/or HARQ-ACK for PTP PDSCHbased MBS service downlink transmission.

A base station(gNB)/a cell shown in FIG. 10 may include a plurality ofTRPs (TRP1 and TRP2). A TRP may correspond to a specific beam/TCIstate/CORESET pool(control resource set pool), etc.

Before an operation of a base station (gNB) and a terminal (UE1 and UE2)shown in FIG. 10 , each of terminals may receive a variety ofconfiguration information for MBS data reception from a base station. Inaddition, each of terminals may be RRC-connected with a base station.

In S1010, each terminal may be RRC-connected with a base station. A RRCconnection may include that each terminal receives from a base station aRRC configuration message or a RRC reconfiguration message.

In S1020, each terminal may receive a variety of configurationinformation from a base station. Configuration information may beprovided for each terminal through at least one RRC message.Configuration information may include at least one of systeminformation, terminal-group specific, or terminal-specific information.Configuration information may include a CFR configuration, a BWPconfiguration, a search space (SS) configuration, a PDSCH configuration,a PUCCH configuration, etc. Some configuration information (e.g., somesystem information) may be acquired by a terminal even before a RRCconnection. Some configuration information may be periodically providedfor terminal(s) from a base station without a request of a terminal ormay be provided from a base station at a request of a terminal.Configuration information may be included in one message or may beincluded in a plurality of messages. In addition, configurationinformation may be provided for terminal(s) through a combination of oneor two or more of downlink control information (DCI), a MAC CE, or a RRCmessage.

For example, a terminal may go into a RRC_CONNECTED mode and report to abase station a message indicating at least one interested MBS service.Such a message may be transmitted from a terminal to a base stationthrough a combination of one or two or more of uplink controlinformation (UCI), a MAC CE, or a RRC message. An interested MBS servicein such a message may refer to one of TMGIs or one of G-RNTIs. A list ofTMGIs or G-RNTIs may be included in a DL message received from a basestation.

For example, a DL message may be a service availability message listingTMGI#1, TMGI#3, TMGI#5 and TMGI#10. When a terminal is interested inTMGI#5, a terminal may indicate order of TMGI#3 in a message. In otherwords, a terminal may report 3 to a base station.

For example, a DL message may be a service availability message listingG-RNTI#1, G-RNTI#3, G-RNTI#5 and G-RNTI#10. When a terminal isinterested in G-RNTI#10, a terminal may indicate order of G-RNTI#10 in amessage. In other words, a terminal may report 4 to a base station.

A base station may provide terminal(s) with a CFR configuration, atleast one group common PDSCH configuration, a SS configuration, etc. Forexample, a base station may provide a CFR configuration, at least onegroup common PDSCH configuration, or a SS configuration, etc. commonlyapplied to UE1 and UE2 through a common message. Alternatively, a basestation may provide a CFR configuration, a group common PDSCHconfiguration, or a SS configuration, etc. applied to each of UE1 andUE2 through an individual message.

For example, a base station which received a MBS-related message from aterminal may provide a CFR configuration to a terminal through a RRCmessage. In addition, a base station which received a MBS-relatedmessage from a terminal may provide to a terminal through a RRC messageat least one group common PDSCH configuration including a TCI state forat least one G-RNTI value. In addition, a base station which received aMBS-related message from a terminal may provide to a terminal through aRRC message a search space configuration including a TCI state for atleast one G-RNTI value. A terminal which received such RRC message(s)may operate based on at least one group common SPS configuration.

For example, a RRC message may be a group common message transmitted ina PTM MCCH or a terminal-dedicated message transmitted in aterminal-specific DCCH (dedicated control channel).

For example, a terminal may be configured with a G-RNTI for each MBS,for each CFR, or for each serving cell. For activation, retransmission,or release of at least one group common SPS configuration, a GC-CS-RNTI(group common-configured scheduling-RNTI) may be configured and used.

When a terminal is not configured with a GC-CS-RNTI for a CFR or aserving cell, when a terminal is configured with a CS-RNTI for a CFR ora serving cell, a terminal may use a CS-RNTI for activation,retransmission, or release of at least one group common SPSconfiguration.

A base station may associate a list of TMGIs or a list of G-RNTIs withone GC-CS-RNTI value. In this case, a base station may provide a list ofTMGIs or a list of G-RNTIs associated with a specific GC-CS-RNTI value.

Each PDSCH configuration (e.g., PDSCH-Config) may include at least oneof the following information elements for a MBS.

TABLE 6 PDSCH-Config ::= SEQUENCE { dataScramblingIdentityPDSCH INTEGER(0..1023) OPTIONAL, -- Need S dmrs-DownlinkForPDSCH-MappingTypeASetupRelease { DMRS-DownlinkConfig } OPTIONAL, -- Need Mdmrs-DownlinkForPDSCH-MappingTypeB SetupRelease { DMRS-DownlinkConfig }OPTIONAL, -- Need M tci-StatesToAddModList SEQUENCE(SIZE(1..maxNrofTCI-States)) OF TCI-State OPTIONAL, -- Need Ntci-StatesToReleaseList SEQUENCE (SIZE(1..maxNrofTCI-States)) OF TCI-StateId OPTIONAL, -- Need N vrb-ToPRB-Interleaver ENUMERATED {n2, n4}OPTIONAL, -- Need S resourceAllocation ENUMERATED {resourceAllocationType0, resourceAllocationType1, dynamicswitch},pdsch-TimeDomainAllocationList SetupRelease { PDSCH-TimeDomainResourceAllocationList } OPTIONAL, -- Need Mpdsch-AggregationFactor ENUMERATED { n2, n4, n8 } OPTIONAL, -- Need SrateMatchPatternToAddModList SEQUENCE (SIZE(1..maxNrofRateMatchPatterns)) OF RateMatchPattern OPTIONAL, -- Need NrateMatchPatternToReleaseList SEQUENCE (SIZE(1..maxNrofRateMatchPatterns)) OF RateMatchPatternId OPTIONAL, -- Need NrateMatchPatternGroup1 RateMatchPatternGroup OPTIONAL, -- Need RrateMatchPatternGroup2 RateMatchPatternGroup OPTIONAL, -- Need Rrbg-Size ENUMERATED {config1, config2}, mcs-Table ENUMERATED {qam256,qam64LowSE} OPTIONAL, -- Need S maxNrofCodeWordsScheduledByDCIENUMERATED {n1, n2} ... }

As in an example of Table 6, a PDSCH configuration for a MBS associatedwith a group common identifier may include at least one of datascrambling identification information (e.g.,dataScramblingIdentityPDSCH), time domain allocation information (e.g.,pdsch-TimeDomainAllocationList), aggregation factor information (e.g.,pdsch-AggregationFactor), rate matching pattern information (e.g.,rateMatchPatternToAddModList), modulation and coding scheme (MCS)information (e.g., mcs-Table), or demodulation reference signal (DMRS)related information (e.g., DMRS-DownlinkConfig).

Hereinafter, examples of the present disclosure related to a CFR and aBWP are described.

A CFR may be configured individually for each terminal or may beconfigured commonly for a plurality of terminals (or terminal groups).In addition, BWP(s) may be configured individually for each terminal andsome BWPs (e.g., an initial BWP) may be configured commonly forterminals. In addition, BWP switching may be applied to each terminal.For example, among a plurality of BWPs configured for a terminal, ifactivation of a second BWP is provided for a terminal when a first BWPis currently activated, switching/change from a first BWP to a secondBWP may be performed.

According to the present disclosure, when a specific condition between aBWP and a CFR is satisfied, MBS service transmission and receptionthrough a CFR may be performed on a currently activated BWP. Anactivated BWP may be an initially activated one or may be a BWPswitched/changed from other BWP. In other words, in each of a BWP beforeswitching and a BWP after switching regarding BWP switching, whether aMBS service is performed may be determined according to whether a CFRand a specific condition are satisfied. A specific condition may includea first condition for whether a CFR is entirely included (or confined)in a BWP, and a second condition for whether a CFR and a BWP have thesame numerology (e.g., (e.g., a SCS and/or CP length). Satisfying aspecific condition may include satisfying at least both a firstcondition and a second condition.

When a specific CFR is confined to at least one (i.e., a plurality of)BWP having the same numerology, a corresponding CFR may be associatedwith corresponding at least one BWP. In this case, a CFR configurationor a BWP configuration may follow the following example.

For example, a CFR configuration may include at least one BWP identifierassociated with a corresponding CFR. For example, when a CFR isassociated with 2 terminal-dedicated BWPs, BWP IDs of corresponding 2terminal-dedicated BWPs may be included in a CFR configuration.

For example, each BWP configuration may include a CFR identifier of aCFR associated with it. For example, when a CFR is associated with 2terminal-dedicated BWPs, each configuration of 2 BWPs may include a CFRidentifier of a CFR associated with it.

For example, BWP identifier(s) of other BWP(s) associated with acorresponding CFR may be included in a BWP configuration of one BWPassociated with a CFR. For example, when a CFR is associated with 2terminal-dedicated BWPs, a configuration for BWP#1 may include a BWP IDof BWP#2.

First, BWP switching between terminal-dedicated BWPs associated with thesame CFR is described.

For BWP switching between terminal-dedicated BWPs associated with thesame CFR, a terminal may continue to receive PTP PDSCH (re)transmissionand/or PTM PDSCH (re)transmission of a specific TB without changing aCFR during/after BWP switching (i.e., maintaining a CFR configuration).

When one same CFR is associated with a plurality of terminal-dedicatedBWPs as described above, it may mean that a CFR is confined to each of aplurality of BWPs (e.g., a CFR is entirely included in a first BWP andis also entirely included in a second BWP) and a CFR and a plurality ofterminal-dedicated BWPs have the same numerology (e.g., a CFR and afirst BWP have the same numerology and a CFR and a second BWP have thesame numerology).

For BWP switching between BWPs associated with the same CFR, a terminalmay maintain at least one of a PDCCH configuration (e.g., PDCCH-Config),a PDSCH configuration (e.g., PDSCH-Config), a SPS configuration (e.g.,SPS-Config), or a PUCCH configuration (e.g., PUCCH-Config) for acorresponding CFR.

In this case, a terminal may maintain a TB of a soft buffer of a HARQprocess associated with reception of group common PDSCH or PTPretransmission.

In addition, a terminal may maintain a HPN (HARQ process number) and aNDI (new data indicator) value of a HARQ process associated withreception of group common PDSCH or PTP retransmission. A NDI representsnew data if its value is changed/toggled and represents that it is notnew data (i.e., retransmission of previous data) if its value is notchanged/toggled.

When a group common PDSCH is received before BWP switching, a terminalmay transmit HARQ-ACK information on a corresponding PDSCH on a PUCCHresource after BWP switching. A PUCCH resource may be allocated to aslot after BWP switching. When a PUCCH resource is allocated to a slotduring BWP switching, a terminal may drop or defer HARQ-ACK.

When a group common SPS of a SPS configuration is activated before BWPswitching, a terminal may consider that a corresponding SPSconfiguration is still activated even after BWP switching. When a groupcommon SPS PDSCH of a SPS configuration is received before BWPswitching, a terminal may monitor SPS retransmission scheduled by DCIwhich is CRC-scrambled by a G-CS-RNTI for a corresponding SPSconfiguration.

When a semi-static PUCCH resource is configured on a CFR, a terminal maymaintain a semi-static PUCCH resource after BWP switching.

Next, BWP switching between terminal-dedicated BWPs which are notassociated with the same CFR is described.

For BWP switching between terminal-dedicated BWPs which are notassociated with the same CFR, a terminal may release a configuration fora previous CFR and apply a configuration for a new CFR.

When a plurality of terminal-dedicated BWPs are not associated with thesame CFR, it may mean that a CFR is not confined to at least one of aplurality of BWPs (e.g., a CFR is not entirely included in a first BWP,or a CFR is not entirely included in a second BWP, or a CFR is notentirely included in both a first BWP and a second BWP) and a CFR and atleast one of a plurality of terminal-dedicated BWPs do not have the samenumerology (e.g., a CFR and a first BWP have a different numerology or aCFR and a second BWP have a different numerology, or a CFR has anumerology different from a first and second BWP) or that a CFR is notconfined to at least one of a plurality of BWPs and a CFR and at leastone of a plurality of terminal-dedicated BWPs do not have the samenumerology.

For BWP switching between BWPs which are not associated with the sameCFR, a terminal may release at least one of a PDCCH configuration (e.g.,PDCCH-Config), a PDSCH configuration (e.g., PDSCH-Config), a SPSconfiguration (e.g., SPS-Config), or a PUCCH configuration (e.g.,PUCCH-Config) for a previous CFR and apply at least one of a PDCCHconfiguration (e.g., PDCCH-Config), a PDSCH configuration (e.g.,PDSCH-Config), a SPS configuration (e.g., SPS-Config), or a PUCCHconfiguration (e.g., PUCCH-Config) for a new CFR.

For example, a terminal may switch a CFR into a CFR associated with achanged/switched BWP.

For example, a terminal may (always) activate a CFR regardless of aG-RNTI. Alternatively, a terminal may (always) activate a correspondingCFR when a CFR is associated with a G-RNTI. Alternatively, a terminalmay deactivate a CFR or may not configure a corresponding CFR for a CFRwhich is not associated with a G-RNTI.

In this case, a terminal may flush a soft buffer of a HARQ processassociated with group common PDSCH or PTP retransmission.

In addition, a terminal may reset a NDI for a HARQ process associatedwith group common PDSCH or PTP retransmission.

When a group common PDSCH is received before BWP switching, a terminalmay not transmit HARQ-ACK information on a corresponding PDSCH on aPUCCH resource after BWP switching.

When a group common SPS of a SPS configuration is activated before BWPswitching, a terminal may consider that a corresponding SPSconfiguration is deactivated, released or suspended after BWP switching.

When a semi-static PUCCH resource is configured on a CFR, a terminal mayrelease a semi-static PUCCH resource after BWP switching.

As an additional or alternative example, when a PUCCH resource isavailable for multicast, a terminal may transmit a MAC CE or UCI (e.g.,HARQ-ACK, SR, etc.) after switching to a CFR. UCI or a MAC CE mayindicate an UE ID as a C-RNTI and/or MBS service identifier (e.g., aTMGI or a G-RNTI for an interested service).

As an additional or alternative example, even after BWP switching, aterminal may still receive a previous CFR until a base stationexplicitly indicates switching to a new CFR. When receiving DCIindicating CFR switching, a terminal may perform switching to a new CFRassociated with a switched BWP.

As an additional or alternative example, for DCI indicating both CFRswitching and BWP switching, a terminal may perform switching to a newBWP and perform switching to a new CFR associated with a switched BWP.Such DCI may include a BWP identifier for a BWP to be switched and oneCFR switching indicator. Alternatively, such DCI may also indicate oneof a new CFR identifier or a BWP identifier associated with a new CFRidentifier.

CORESET identifier(s) associated with a BWP may be applied equally asCORESET ID(s) of a CFR associated with a corresponding BWP. A CORESET IDincluded in a PDCCH configuration may be unique across all CFRsconfigured for a specific serving cell and associated BWPs.Alternatively, a CORESET ID included in a PDCCH configuration may beconfigured only for one of a BWP or a CFR for a specific serving cell.Alternatively, a CORESET ID included in a PDCCH configuration may beshared for a BWP and a CFR for a specific serving cell. Whether aCORESET ID is configured for both a CFR and a BWP associated with it maybe determined by a base station.

For the above-described examples, in order to transmit to a base stationHARQ-ACK information indicating whether a terminal successfully decodesMBS transmission from a base station (i.e., HARQ-ACK collectively refersto HARQ feedback information including ACK or NACK), a base station maypre-provide a PUCCH configuration to a terminal. When a terminalreceives a MBS service, a base station may pre-configure to a terminal aseparate PUCCH configuration for MBS HARQ-ACK (i.e., a PUCCHconfiguration for multicast) which is distinguished from a PUCCHconfiguration for unicast.

In S1030, each terminal may perform an operation of PDCCH monitoring andDCI reception based on a specific RNTI and PDSCH reception based onscheduling information included in DCI.

When a search space (SS) for a configured CFR is configured for aterminal, a terminal may monitor a PDCCH to receive CRC-scrambled DCI asa group common identifier (e.g., a G-RNTI or a G-CS-RNTI) on a SSconfigured in a configured CFR.

When a data unit is available in a MTCH of a MRB (MBS radio bearer) fora MBS service, a base station may construct a TB including acorresponding data unit to transmit it during a specific SPS PDSCHoccasion. A specific SPS PDSCH, according to service-to-resourcemapping, may be associated with a MTCH of a MRB for a corresponding MBSservice, may be associated with a TGMI of a corresponding MBS service,may be associated with a short ID of a corresponding MBS service, or maybe associated with a G-RNTI mapped to a corresponding MBS service.

For group common dynamic scheduling of a TB, a base station may transmitDCI to a terminal through a PDCCH and a CRC of corresponding DCI may bescrambled with G-RNTI, G-CS-RNTI or CS-RNTI. A PDCCH may be a groupcommon PDCCH or a terminal-specific PDCCH. Corresponding DCI may includeat least one of the following fields:

Identifier Field of DCI Format: This format may indicate one of aMBS-specific DCI format or the existing DCI format for a MBS.

Carrier Identifier Field: This field may indicate a serving cell of aBWP associated with a CFR that a group common PDCCH/PDSCH is transmittedor a cell of a CFR (a serving cell or a MBS specific cell).

BWP Indicator Field: This field may indicate a BWP ID of a BWPassociated with a CFR that a group common PDCCH/PDSCH is transmitted ora BWP ID allocated to a CFR. A frequency domain resource allocationfield; a

time domain resource allocation field; a VRB-to-PRB mapping field; a PRBbundling size indicator field; a rate matching indicator field; aZP(zero power) CSI-RS trigger field; a MCS field, a NDI field; aRV(redundancy version) field; a HARQ process number (HPN) field; adownlink allocation index (DAI) field; a transmission power control(TPC) command field for a PUCCH to be scheduled; a PUCCH resourceindicator field; a PDSCH-to-HARQ feedback timing indicator field; anantenna port(s) field; a transmission configuration indication (TCI)field; a SRS request field; a DMRS sequence initialization field; apriority indicator field, etc.

For group common dynamic scheduling, a base station may provide thefollowing service-to-resource mapping information through a group commonor terminal-specific RRC message or a group common or terminal-specificMAC CE. Service-to-resource mapping information may be provided for aMBS service identified by a TMGI, a G-RNTI, or a GC-CS-RNTI. Data of aMBS service may be transmitted on a MRB of a multicast traffic logicalchannel (i.e., a MTCH) associated with a MBS service. A RRC message maybe a group common message transmitted in a PTM MCCH or may be aterminal-dedicated message transmitted in a terminal-specific DCCH. DCIscheduling a PDSCH carrying MBS service data may indicate at least oneof a short ID, a MTCH ID, a MRB ID, a G-RNTI value or a TMGI value for acorresponding MBS service.

When a terminal receives DCI which is CRC-scrambled by an interestedG-RNTI, a terminal, based on a predetermined mapping relation, maydetermine MBS service(s) associated with a predetermined identifier foreach PDSCH occasion. A predetermined mapping relation may include atleast one of mapping between MBS services and HPNs indicated by DCI, orif available, mapping between MBS services and short ID(s) indicated byDCI. A predetermined identifier may be at least one of a short ID, aMTCH ID, a MRB ID, a G-RNTI value or a TMGI value.

When a terminal is interested in determined MBS service(s), a terminalmay receive PDSCH transmission scheduled by corresponding DCI. When aterminal is not interested in determined MBS service(s), a terminal maynot receive PDSCH transmission scheduled by corresponding DCI.

In S1040, according to a decoding state for PDSCH transmission, aterminal may transmit a HARQ feedback to a base station.

For example, when receiving group common DCI indicating PUCCHresource(s) for MBS HARQ-ACK, a terminal may transmit HARQ-ACK through aPUCCH after receiving a PDSCH scheduled by corresponding DCI.

In addition, a base station may provide a multicast SPS by configuring aterminal common SPS. For a group common SPS PDSCH (i.e., scheduled byRRC, not by DCI), a group common PUCCH resource used as NACK-only basedHARQ-ACK (i.e., ACK is not fedback and only NACK is fedback) may beconfigured semi-statically for at least one group common SPSconfiguration. Alternatively, a terminal-specific PUCCH resource used asACK/NACK-based HARQ-ACK (i.e., ACK or NACK is fed back) may beconfigured for at least one group common SPS configuration.Alternatively, a group common PUCCH resource for ACK and a group commonPUCCH resource for NACK may be separately configured for at least onegroup common SPS configuration.

For different SPS configurations, the same PUCCH resource or a differentPUCCH resource may be configured.

When the same PUCCH resource is allocated to different SPS PDSCHs of adifferent SPS configuration, one HARQ-ACK bit may indicate ACK or NACKfor all SPS PDSCHs. In this case, when all SPS PSCHs are successfullyreceived/decoded, a terminal may indicate ACK. In addition, when atleast one SPS PDSCH is not successfully received/decoded, a terminal mayindicate NACK. Alternatively, different HACQ-ACK bits may indicate ACKor NACK of a different SPS PDSCH, respectively.

When a different PUCCH resource is allocated to different SPS PDSCHs ofa different SPS configuration, different HACQ-ACK bits may indicate ACKor NACK of a different SPS PDSCH, respectively.

When a PUCCH resource is not explicitly indicated for SPS configurationindex N, a terminal may determine that a PUCCH resource for SPSconfiguration index N−k (or N+k) is also used for SPS configurationindex N (k is 1 or other integer). Alternatively, when a PUCCH resourceis not explicitly indicated for SPS configuration index N, a terminalmay determine that a HARQ-ACK operation is disabled for a SPS PDSCH ofcorresponding SPS configuration index N.

When PUCCH-config for multicast is configured, a terminal may determinethat a PUCCH resource for group common SPS configuration index(s) isdetermined based on PUCCH-config for multicast and a PUCCH resource forterminal-specific SPS configuration index(s) is determined based onPUCCH-config for unicast.

When PUCCH-config for multicast is not configured, a terminal maydetermine that a PUCCH resource for group common SPS configurationindex(s) is determined based on PUCCH-config for unicast.

Next, for group common SPS retransmission, a PUCCH resource may beallocated by DCI which is CRC-scrambled by a G-CN-RNTI.

When a terminal determines a PUCCH resource, a terminal may considercorresponding group common SPS retransmission as a group common PDSCHscheduled by DCI.

When PUCCH-config for multicast is configured, a terminal may determinethat a PUCCH resource for group common SPS retransmission is determinedbased on PUCCH-config for multicast.

When PUCCH-config for multicast is not configured, a terminal maydetermine that a PUCCH resource for group common SPS retransmission isdetermined based on PUCCH-config for unicast. When a terminal determinesa PUCCH resource, a terminal may consider corresponding SPSretransmission as a unicast PDSCH (or a group common PDSCH).

For terminal-specific SPS retransmission of a TB which was firsttransmitted by a group common SPS PDSCH, a PUCCH resource may beallocated by DCI which is CRC-scrambled by a SC-RNTI.

In this case, when a terminal determines a PUCCH resource, a terminalmay consider terminal-specific SPS retransmission as a unicast PDSCH.Alternatively, when a terminal determines a PUCCH resource, a terminalmay consider that corresponding terminal-specific SPS retransmission isa group common PDSCH scheduled by DCI.

When PUCCH-config for multicast is configured, a terminal may determinethat a PUCCH resource for group common SPS retransmission is determinedbased on PUCCH-config for multicast. Alternatively, althoughPUCCH-config for multicast is configured, a terminal may determine thata PUCCH resource for group common SPS retransmission is determined basedon PUCCH-config for unicast.

When PUCCH-config for multicast is not configured, a terminal maydetermine that a PUCCH resource for group common SPS retransmission isdetermined based on PUCCH-config for unicast.

NACK-only based HARQ-ACK may be applied to SPS PDSCH retransmission or aterminal-specific ACK/NACK based HARQ-ACK may be also applied.

As in S1040 for UE2 in an example of FIG. 10 , when decoding for a TB ata PDSCH transmission occasion is not successful, a terminal may transmitHARQ NACK to a base station on a PUCCH resource determined as in theabove-described examples in a configured UL CFR.

With a corresponding PUCCH resource, a terminal may also transmitHARQ-ACK information for other PDSCH transmission (e.g., a unicast SPSPDSCH, a dynamic unicast PDSCH, PTP retransmission, and/or a dynamicgroup common PDSCH). In this case, in order to multiplex on a PUCCHHARQ-ACK for a variety of PDSCHs in a (sub) slot (e.g., a SPS PSCH formulticast, a SPS PDSCH for unicast, a multicast PDSCH which isdynamically scheduled, and/or a unicast PDSCH which is dynamicallyscheduled), a terminal may configure a codebook based on theabove-described examples.

In addition, when an aggregation factor (e.g., pdsch-AggregationFactor)is configured for a G-RNTI or the number of repetitions (e.g.,repetition number) is indicated by a base station in DCI, a TB scheduledby group common DCI may be repeated. For example, when a configurationis performed, in each symbol allocation among each of consecutive slotscorresponding to an aggregation factor or among each of consecutiveslots corresponding to the number of repetitions, N-th HARQ transmissionof a TB may be transmitted.

For HARQ-ACK for slot-based group common PDSCH repetition of a TB, whenan aggregation factor (e.g., pdsch-AggregationFactor) is configured fora G-RNTI or when the number of repetitions (e.g., repetition number) isindicated by a base station in DCI which is CRC-scrambled by a G-RNTI, abase station may allocate PUCCH resources as follows.

For example, multiple PUCCH resources may be allocated by group commonDCI scheduling slot-based group common PDSCH repeat transmission.

Alternatively, periodic PUCCH resources may be allocated to a terminalreceiving a G-RNTI.

Alternatively, for G-RNTI(s), or for a CFR that group common PDSCHrepeat transmission is scheduled, periodic PUCCH resources may beallocated. If ACK/NACK-based HARQ-ACK is configured, different terminalsmay select a different PUCCH resource.

As in S1040 for UE1 in an example of FIG. 10 , when a terminalsuccessfully receives/decodes a TB in HPN#i before the end of slot-basedgroup common PDSCH repeat transmission and a PUCCH resource for HARQ-ACKof a corresponding TB is available before the end of slot-based groupcommon PDSCH repeat transmission, a terminal may transmit ACK on a PUCCHresource before the end of slot-based group common PDSCH repeattransmission.

For example, a terminal may skip ACK transmission on other PUCCHresource after the end of slot-based group common PDSCH repeattransmission. In this case, a terminal may receive other TB in HPN#i.

Alternatively, a terminal may retransmit ACK on other PUCCH resourceafter the end of slot-based group common PDSCH repeat transmission.

Alternatively, a terminal may de-prioritize ACK transmission on otherPUCCH resource after the end of slot-based group common PDSCH repeattransmission.

In another example, a terminal may transmit ACK on a terminal-specificPUCCH resource allocated for a unicast PDSCH.

In another example, a terminal may not transmit ACK on a PUCCH resourcebefore the end of slot-based group common PDSCH repeat transmission. Aterminal may perform HARQ-ACK transmission on a PUCCH resource indicatedby PUCCH resource indication information (PRI) of DCI scheduling a groupcommon PDSCH after the end of slot-based group common PDSCH repeattransmission.

When a terminal successfully receives a TB (e.g., in N-th HARQtransmission) and monitors HARQ retransmission for a corresponding TB byterminal-specific DCI or group common DCI (e.g., N+k-th HARQtransmission), a terminal may operate as follows.

For example, a terminal may skip ACK transmission on a PUCCH resourceallocated by DCI.

Alternatively, a terminal may retransmit ACK on a PUCCH resourceallocated by DCI.

Alternatively, a terminal may de-prioritize ACK transmission on a PUCCHresource allocated by DCI.

In S1050, BWP switching may be indicated for a terminal. BWP switchingmay be performed separately from HARQ-ACK feedback and HARQtransmission/retransmission and BWP switching may be also performed forHARQ retransmission.

In an example of FIG. 10 , MBS data/TB transmission may be successfullyperformed for UE1 and a base station may indicate BWP switching for newdata transmission or for other purpose S1050. When a BWP to be switchedand the existing CFR do not satisfy a specific condition (e.g., a CFR isconfined to a BWP and a CFR and a BWP have the same numerology), aterminal may release the existing CFR S1060.

In an example of FIG. 10 , UE2 may transmit NACK because it does notsuccessfully decode a PDSCH including MBS data and a base station mayindicate BWP switching to UE2 S1050. When a BWP to be switched and theexisting CFR satisfy a specific condition (e.g., a CFR is confined to aBWP and a CFR and a BWP have the same numerology), a terminal maymaintain the existing CFR S1070. UE2 may perform an operation of MBSdata reception (i.e., PDCCH monitoring, DCI reception, PDSCH receptionscheduled by DCI) on a switched BWP2 S1080. When UE2 does not succeed inPDSCH decoding, HARQ NACK may be transmitted to a base station through aPUCCH S1090.

When a base station receives HARQ NACK for a PDSCH transmitted based ona specific TCI state, a base station may retransmit a PDCCH and a PDSCHbased on a corresponding TCI state in a DL CFR configured forretransmission of a corresponding TB. In order to receive retransmissionof a corresponding TB, a terminal, based on a corresponding TCI state ona search space configured in a DL CFR, may monitor a group common and/orterminal-specific PDCCH.

A base station may retransmit a TB by a terminal-specific PDCCH only forone terminal in a group. As the remaining terminals in a groupsuccessfully received a corresponding TB, retransmission for acorresponding TB may not be received.

When a terminal receives a PDCCH for TB retransmission, a terminal mayreceive a PDSCH scheduled by DCI of a corresponding PDCCH.

When a terminal successfully decodes a TB on a PDSCH, based on apredetermined mapping relation, a terminal may consider that a decodedTB is associated with a MTCH, a MRB, a TMGI, a G-RNTI, and/or a short IDof a MBS service. A predetermined mapping relation may include mappingbetween MBS services and HPNs indicated by DCI, and/or if available,mapping between MBS services and short ID(s) indicated by DCI.

When TB decoding at a PDSCH transmission occasion is successful, aterminal may transmit HARQ-ACK information to a base station on a PUCCHresource according to the above-described examples in a configured ULCFR.

With a corresponding PUCCH resource, a terminal may also transmitHARQ-ACK information for other PDSCH transmission (e.g., a unicast SPSPDSCH, a dynamic unicast PDSCH, PTP retransmission, and/or a dynamicgroup common PDSCH). In this case, in order to multiplex on a PUCCHHARQ-ACK for a variety of PDSCHs in a (sub) slot (e.g., a SPS PSCH formulticast, a SPS PDSCH for unicast, a multicast PDSCH which isdynamically scheduled, and/or a unicast PDSCH which is dynamicallyscheduled), a terminal may configure a codebook based on theabove-described examples.

When collision occurs, a terminal may perform monitoring of a multicastPDCCH and reception of a multicast PDSCH as follows.

When a multicast PUCCH is overlapped with unicast DL reception which isconfigured semi-statically; or when a multicast PUCCH is overlapped withunicast UL transmission which is configured semi-statically; or when amulticast PUCCH is overlapped with sidelink transmission and receptionwhich is configured semi-statically, a terminal may defer HARQ-ACK forMBS SPS HARQ-ACK and transmit HARQ-ACK for MBS HARQ-ACK indicated by aPRI of DCI.

When a multicast PUCCH is overlapped with unicast DL reception which isconfigured dynamically; or when a multicast PUCCH is overlapped withunicast UL transmission which is configured dynamically, a terminal maydefer or drop HARQ-ACK (e.g., corresponding to a case in which HARQ-ACKis a low priority (LP) and other transmission/reception is a highpriority (HP)), or a terminal may transmit HARQ-ACK (e.g., correspondingto a case in which HARQ-ACK is a HP and other transmission/reception isa LP).

When a multicast PUCCH is overlapped with a dynamic multicast PDSCH, aterminal may drop HARQ-ACK up to a K1 value (e.g., when multicast is aHP), or a terminal may transmit HARQ-ACK (e.g., when multicast is a LP).

When a multicast PUCCH is overlapped with a multicast SPS PDSCH, aterminal may defer or drop HARQ-ACK.

When a terminal triggers a RACH, a terminal may perform monitoring of agroup common PDCCH and reception of a group common PDSCH as follows.

A terminal may monitor a group common PDCCH as follows after triggeringa RACH. When a RACH is triggered, a terminal may suspend group commonPDCCH monitoring and group common PDSCH reception. A terminal may resumegroup common PDCCH monitoring/reception after receiving one of MSG1(e.g., PRACH preamble transmission), MSG2 (e.g., random access response(RAR) reception), MSG3 (e.g., PUSCH transmission based on UL grant of aRAR) and MSG4 (e.g., contention resolution message reception) of a4-step RACH operation. For a 4-step RACH operation, a terminal may applya high priority to transmission and reception of MSG1, MSG2, MSG3, andMSG4 compared with reception of a group common PDCCH/PDSCH and HARQ-ACKtransmission for a group common PDSCH. A terminal may resume groupcommon PDCCH monitoring/reception after receiving one of MSGA (e.g.,PRACH preamble and PUSCH transmission) and MSGB (e.g., a RAR and acontention resolution message) of a 2-step RACH operation. For a 2-stepRACH operation, a terminal may apply a high priority to transmission andreception of MSGA and MSGB compared with reception of a group commonPDCCH/PDSCH and HARQ-ACK transmission for a group common PDSCH.

A terminal may transmit MSB HARQ-ACK on a PUCCH right after MSG2 or MSGBreception (for a contention free (CF) RACH procedure) or right afterfirst MSG3 transmission (for a contention-based RACH procedure). Aterminal may not perform MBS HARQ-ACK transmission without ULsynchronization. MSG3 may not be multiplexed with PUCCH ACK/NACK. Aterminal may disable HARQ-ACK before MSG3 transmission (for acontention-based RACH procedure) and enable HARQ-ACK after MSG3transmission. A terminal may disable HARQ-ACK before MSG2/MSGBtransmission (for a CF-RACH procedure) and enable HARQ-ACK afterMSG2/MSGB transmission.

General Device to which the Present Disclosure may be applied

FIG. 11 is a diagram which illustrates a block diagram of a wirelesscommunication system according to an embodiment of the presentdisclosure.

In reference to FIG. 11 , a first wireless device 100 and a secondwireless device 200 may transmit and receive a wireless signal through avariety of radio access technologies (e.g., LTE, NR).

A first wireless device 100 may include one or more processors 102 andone or more memories 104 and may additionally include one or moretransceivers 106 and/or one or more antennas 108. A processor 102 maycontrol a memory 104 and/or a transceiver 106 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. For example, aprocessor 102 may transmit a wireless signal including firstinformation/signal through a transceiver 106 after generating firstinformation/signal by processing information in a memory 104. Inaddition, a processor 102 may receive a wireless signal including secondinformation/signal through a transceiver 106 and then store informationobtained by signal processing of second information/signal in a memory104. A memory 104 may be connected to a processor 102 and may store avariety of information related to an operation of a processor 102. Forexample, a memory 104 may store a software code including commands forperforming all or part of processes controlled by a processor 102 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. Here, aprocessor 102 and a memory 104 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 106 may be connected to aprocessor 102 and may transmit and/or receive a wireless signal throughone or more antennas 108. A transceiver 106 may include a transmitterand/or a receiver. A transceiver 106 may be used together with a RF(Radio Frequency) unit. In the present disclosure, a wireless device maymean a communication modem/circuit/chip.

A second wireless device 200 may include one or more processors 202 andone or more memories 204 and may additionally include one or moretransceivers 206 and/or one or more antennas 208. A processor 202 maycontrol a memory 204 and/or a transceiver 206 and may be configured toimplement description, functions, procedures, proposals, methods and/oroperation flows charts included in the present disclosure. For example,a processor 202 may generate third information/signal by processinginformation in a memory 204, and then transmit a wireless signalincluding third information/signal through a transceiver 206. Inaddition, a processor 202 may receive a wireless signal including fourthinformation/signal through a transceiver 206, and then store informationobtained by signal processing of fourth information/signal in a memory204. A memory 204 may be connected to a processor 202 and may store avariety of information related to an operation of a processor 202. Forexample, a memory 204 may store a software code including commands forperforming all or part of processes controlled by a processor 202 or forperforming description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure. Here, aprocessor 202 and a memory 204 may be part of a communicationmodem/circuit/chip designed to implement a wireless communicationtechnology (e.g., LTE, NR). A transceiver 206 may be connected to aprocessor 202 and may transmit and/or receive a wireless signal throughone or more antennas 208. A transceiver 206 may include a transmitterand/or a receiver. A transceiver 206 may be used together with a RFunit. In the present disclosure, a wireless device may mean acommunication modem/circuit/chip.

Hereinafter, a hardware element of a wireless device 100, 200 will bedescribed in more detail. It is not limited thereto, but one or moreprotocol layers may be implemented by one or more processors 102, 202.For example, one or more processors 102, 202 may implement one or morelayers (e.g., a functional layer such as PHY, MAC, RLC, PDCP, RRC,SDAP). One or more processors 102, 202 may generate one or more PDUs(Protocol Data Unit) and/or one or more SDUs (Service Data Unit)according to description, functions, procedures, proposals, methodsand/or operation flow charts included in the present disclosure. One ormore processors 102, 202 may generate a message, control information,data or information according to description, functions, procedures,proposals, methods and/or operation flow charts included in the presentdisclosure. One or more processors 102, 202 may generate a signal (e.g.,a baseband signal) including a PDU, a SDU, a message, controlinformation, data or information according to functions, procedures,proposals and/or methods disclosed in the present disclosure to provideit to one or more transceivers 106, 206. One or more processors 102, 202may receive a signal (e.g., a baseband signal) from one or moretransceivers 106, 206 and obtain a PDU, a SDU, a message, controlinformation, data or information according to description, functions,procedures, proposals, methods and/or operation flow charts included inthe present disclosure.

One or more processors 102, 202 may be referred to as a controller, amicro controller, a micro processor or a micro computer. One or moreprocessors 102, 202 may be implemented by a hardware, a firmware, asoftware, or their combination. In an example, one or moreASICs(Application Specific Integrated Circuit), one or more DSPs(DigitalSignal Processor), one or more DSPDs(Digital Signal Processing Device),one or more PLDs(Programmable Logic Device) or one or more FPGAs(FieldProgrammable Gate Arrays) may be included in one or more processors 102,202. Description, functions, procedures, proposals, methods and/oroperation flow charts included in the present disclosure may beimplemented by using a firmware or a software and a firmware or asoftware may be implemented to include a module, a procedure, afunction, etc. A firmware or a software configured to performdescription, functions, procedures, proposals, methods and/or operationflow charts included in the present disclosure may be included in one ormore processors 102, 202 or may be stored in one or more memories 104,204 and driven by one or more processors 102, 202. Description,functions, procedures, proposals, methods and/or operation flow chartsincluded in the present disclosure may be implemented by using afirmware or a software in a form of a code, a command and/or a set ofcommands.

One or more memories 104, 204 may be connected to one or more processors102, 202 and may store data, a signal, a message, information, aprogram, a code, an instruction and/or a command in various forms. Oneor more memories 104, 204 may be configured with ROM, RAM, EPROM, aflash memory, a hard drive, a register, a cash memory, a computerreadable storage medium and/or their combination. One or more memories104, 204 may be positioned inside and/or outside one or more processors102, 202. In addition, one or more memories 104, 204 may be connected toone or more processors 102, 202 through a variety of technologies suchas a wire or wireless connection.

One or more transceivers 106, 206 may transmit user data, controlinformation, a wireless signal/channel, etc. mentioned in methods and/oroperation flow charts, etc. of the present disclosure to one or moreother devices. One or more transceivers 106, 206 may receiver user data,control information, a wireless signal/channel, etc. mentioned indescription, functions, procedures, proposals, methods and/or operationflow charts, etc. included in the present disclosure from one or moreother devices. For example, one or more transceivers 106, 206 may beconnected to one or more processors 102, 202 and may transmit andreceive a wireless signal. For example, one or more processors 102, 202may control one or more transceivers 106, 206 to transmit user data,control information or a wireless signal to one or more other devices.In addition, one or more processors 102, 202 may control one or moretransceivers 106, 206 to receive user data, control information or awireless signal from one or more other devices. In addition, one or moretransceivers 106, 206 may be connected to one or more antennas 108, 208and one or more transceivers 106, 206 may be configured to transmit andreceive user data, control information, a wireless signal/channel, etc.mentioned in description, functions, procedures, proposals, methodsand/or operation flow charts, etc. included in the present disclosurethrough one or more antennas 108, 208. In the present disclosure, one ormore antennas may be a plurality of physical antennas or a plurality oflogical antennas (e.g., an antenna port). One or more transceivers 106,206 may convert a received wireless signal/channel, etc. into a basebandsignal from a RF band signal to process received user data, controlinformation, wireless signal/channel, etc. by using one or moreprocessors 102, 202. One or more transceivers 106, 206 may convert userdata, control information, a wireless signal/channel, etc. which areprocessed by using one or more processors 102, 202 from a basebandsignal to a RF band signal. Therefore, one or more transceivers 106, 206may include an (analogue) oscillator and/or a filter.

Embodiments described above are that elements and features of thepresent disclosure are combined in a predetermined form. Each element orfeature should be considered to be optional unless otherwise explicitlymentioned. Each element or feature may be implemented in a form that itis not combined with other element or feature. In addition, anembodiment of the present disclosure may include combining a part ofelements and/or features. An order of operations described inembodiments of the present disclosure may be changed. Some elements orfeatures of one embodiment may be included in other embodiment or may besubstituted with a corresponding element or a feature of otherembodiment. It is clear that an embodiment may include combining claimswithout an explicit dependency relationship in claims or may be includedas a new claim by amendment after application.

It is clear to a person skilled in the pertinent art that the presentdisclosure may be implemented in other specific form in a scope notgoing beyond an essential feature of the present disclosure.Accordingly, the above-described detailed description should not berestrictively construed in every aspect and should be considered to beillustrative. A scope of the present disclosure should be determined byreasonable construction of an attached claim and all changes within anequivalent scope of the present disclosure are included in a scope ofthe present disclosure.

A scope of the present disclosure includes software ormachine-executable commands (e.g., an operating system, an application,a firmware, a program, etc.) which execute an operation according to amethod of various embodiments in a device or a computer and anon-transitory computer-readable medium that such a software or acommand, etc. are stored and are executable in a device or a computer. Acommand which may be used to program a processing system performing afeature described in the present disclosure may be stored in a storagemedium or a computer-readable storage medium and a feature described inthe present disclosure may be implemented by using a computer programproduct including such a storage medium. A storage medium may include ahigh-speed random-access memory such as DRAM, SRAM, DDR RAM or otherrandom-access solid state memory device, but it is not limited thereto,and it may include a nonvolatile memory such as one or more magneticdisk storage devices, optical disk storage devices, flash memory devicesor other nonvolatile solid state storage devices. A memory optionallyincludes one or more storage devices positioned remotely fromprocessor(s). A memory or alternatively, nonvolatile memory device(s) ina memory include a non-transitory computer-readable storage medium. Afeature described in the present disclosure may be stored in any one ofmachine-readable mediums to control a hardware of a processing systemand may be integrated into a software and/or a firmware which allows aprocessing system to interact with other mechanism utilizing a resultfrom an embodiment of the present disclosure. Such a software or afirmware may include an application code, a device driver, an operatingsystem and an execution environment/container, but it is not limitedthereto.

Here, a wireless communication technology implemented in a wirelessdevice 100, 200 of the present disclosure may include NarrowbandInternet of Things for a low-power communication as well as LTE, NR and6G. Here, for example, an NB-IoT technology may be an example of aLPWAN(Low Power Wide Area Network) technology, may be implemented in astandard of LTE Cat NB1 and/or LTE Cat NB2, etc. and is not limited tothe above-described name. Additionally or alternatively, a wirelesscommunication technology implemented in a wireless device 100, 200 ofthe present disclosure may perform a communication based on a LTE-Mtechnology. Here, in an example, a LTE-M technology may be an example ofa LPWAN technology and may be referred to a variety of names such as aneMTC (enhanced Machine Type Communication), etc. For example, an LTE-Mtechnology may be implemented in at least any one of various standardsincluding 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTEnon-BL(non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine TypeCommunication, and/or 7) LTE M and so on and it is not limited to theabove-described name. Additionally or alternatively, a wirelesscommunication technology implemented in a wireless device 100, 200 ofthe present disclosure may include at least any one of a ZigBee, aBluetooth and a low power wide area network (LPWAN) considering alow-power communication and it is not limited to the above-describedname. In an example, a ZigBee technology may generate PAN(personal areanetworks) related to a small/low-power digital communication based on avariety of standards such as IEEE 802.15.4, etc. and may be referred toas a variety of names.

A method proposed by the present disclosure is mainly described based onan example applied to 3GPP LTE/LTE-A, 5G system, but may be applied tovarious wireless communication systems other than the 3GPP LTE/LTE-A, 5Gsystem.

1-18. (canceled)
 19. A method performed by a terminal in a wirelesscommunication system, the method comprising: receiving, from a network,configuration information for a common frequency resource (CFR) forgroup common data associated with a group-radio network temporaryidentifier (G-RNTI); receiving, from the network, information on aplurality of bandwidth parts (BWPs); monitoring a physical downlinkcontrol channel (PDCCH) for detecting a downlink control information(DCI) format which is cyclic redundancy check(CRC)-scrambled by theG-RNTI on an active first BWP, based on the active first BWP and aspecific frequency resource provided by the configuration informationfor the CFR having a same subcarrier spacing (SCS) and a same cyclicprefix length, and the active first BWP including all resource blocks ofthe specific frequency resource; switching to a second BWP to activatethe second BWP and deactivate the first BWP; and monitoring a PDCCH fordetecting a DCI format which is CRC-scrambled by the G-RNTI on theactive second BWP, based on the active second BWP and the specificfrequency resource provided by the configuration information for the CFRhaving a same SCS and a same cyclic prefix length, and the active secondBWP including all resource blocks of the specific frequency resource.20. The method according to claim 19, the group common data is receivedthrough a physical downlink shared channel (PDSCH) scheduled by the DCIformat.
 21. The method according to claim 19, wherein: information onthe G-RNTI and a Temporary Mobile Group Identity (TMGI) associated withthe group common data is provided from the network.
 22. The methodaccording to claim 19, wherein: the configuration information for theCFR and the information on the plurality of BWPs including the first BWPand the second BWP are separately provided.
 23. The method according toclaim 19, wherein: configuration information on a PDSCH for group commondata associated with the G-RNTI and the information on the plurality ofBWPs including the first BWP and the second BWP are separately provided.24. The method according to claim 23, wherein the configurationinformation on the PDSCH includes: at least one of data scramblingidentification information, time domain allocation information,aggregation factor information, rate matching pattern information,modulation and coding scheme (MCS) information, or demodulationreference signal (DMRS) related information.
 25. The method according toclaim 19, wherein: the terminal is in a radio resource control(RRC)_CONNECTED state.
 26. The method according to claim 19, wherein:the plurality of BWPs are configured for one serving cell.
 27. Themethod according to claim 19, wherein: the group common data is receivedthrough a broadcast PDSCH or a multicast PDSCH.
 28. A terminal in awireless communication system, the terminal comprising: at least onetransceiver; and at least one processor connected to the at least onetransceiver, wherein the at least one processor is configured to:receive, through the at least one transceiver, from a network,configuration information for a common frequency resource (CFR) forgroup common data associated with a group-radio network temporaryidentifier (G-RNTI); receive, through the at least one transceiver, fromthe network, information on a plurality of bandwidth parts (BWPs);monitor a physical downlink control channel (PDCCH) for detecting adownlink control information (DCI) format which is cyclic redundancycheck(CRC)-scrambled by the G-RNTI on an active first BWP, based on theactive first BWP and a specific frequency resource provided by theconfiguration information for the CFR having a same subcarrier spacing(SCS) and a same cyclic prefix length, and the active first BWPincluding all resource blocks of the specific frequency resource; switchto a second BWP to activate the second BWP and deactivate the first BWP;and monitor a PDCCH for detecting a DCI format which is CRC-scrambled bythe G-RNTI on the active second BWP, based on the active second BWP andthe specific frequency resource provided by the configurationinformation for the CFR having a same SCS and a same cyclic prefixlength, and the active second BWP including all resource blocks of thespecific frequency resource.
 29. A base station in a wirelesscommunication system, the base station comprising: at least onetransceiver; and at least one processor connected to the at least onetransceiver, wherein the at least one processor is configured to:transmit, through the at least one transceiver, to a terminal,configuration information for a common frequency resource (CFR) forgroup common data associated with a group-radio network temporaryidentifier (G-RNTI); transmit, through the at least one transceiver, tothe terminal, information on a plurality of bandwidth parts (BWPs);transmit a downlink control information (DCI) format which is cyclicredundancy check(CRC)-scrambled by the G-RNTI through a physicaldownlink control channel (PDCCH) on an active first BWP, based on theactive first BWP and a specific frequency resource provided by theconfiguration information for the CFR having a same subcarrier spacing(SCS) and a same cyclic prefix length, and the active first BWPincluding all resource blocks of the specific frequency resource;transmit through the at least one transceiver to the terminalinformation on switching to a second BWP to activate the second BWP anddeactivate the first BWP; and transmit a DCI format which isCRC-scrambled by the G-RNTI through a PDCCH on an active second BWP,based on the active second BWP and the specific frequency resourceprovided by the configuration information for the CFR having a SCS and asame cyclic prefix length, and the active second BWP including allresource blocks of the specific frequency resource.